Moran, Theodore H
Princeton University Press, 1974
Buku Teks
Peterson, Wallace C.
W.W. Norton & Co., 1962
Buku Teks
Artikel Jurnal
McGuire, Paul
Oxford University Press, 1948
Buku Teks SO
Deutsch, Karl Wolfgang, 1912-1992
Houghton Mifflin, 1970
Buku Teks